George H. Fetterman

POLYARTERITIS NODOSA IN INFANCY.

Two fatal cases of polyarteritis nodosa in infants are reported with clinical and postmortem findings. Study of the clinical features of, these 2 cases and 18 others from the literature suggests that a more or less constant clinical syndrome exists. Awareness of the symptoms, signs, and laboratory findings common to many of these cases should make it possible to arrive at a presumptive diagnosis during life. The frequency of coronary artery involvement in the infantile form of polyarteritis nodosa is stressed.

The Application of Renal Microdissection to the Study of Kidney Disease in Infancy and Childhood

The methods of renal microdissection are of essential value in the study of kid ney problems in infancy and childhood. Characteristics of nephrons in normal kidneys in the pediatric age group are presented, as well as examples of some of the proximal tubular abnormalities which have been demonstrated in renal disease in infancy and childhood. These illustrations were shown in an Exhibit at the American Association of Urology Meeting and won an Honorable Mention; and at the College of American Pathologists ASCP Meeting where it re ceived the Gold Award in the Educational Division.

Microdissection Studies of the Structural Alterations Induced in Rat Kidneys by Experimental Postischemic Acute Renal Failure

A unique opportunity presented itself for a morphologic study of experimental unilateral acute renal failure (ARF) in male rats. The ARF had been induced in the rats by temporary occlusion (1h) of the left renal artery. Twenty-nine rats were divided into subsets as follows: 2-3 h, 24 h, 1 week, 2, 4, 8, and 12 weeks following release of occlusion. Microdissection showed a heterogeneous population of abnormally structured proximal tubules in which the regressive lesions of tubular necrosis were combined with the progressive reaction of repair. The lesions demonstrated are reminiscent of those which have been described in ARF in the human and in experimental animals. Many proximal tubules in the 2- to 3-hour subset presented 1-3 disruptive lesions (DLs) while greater numbers of proximal tubules from the 24-hour group presented 1-5 DLs. Many proximal tubules presented no DLs, but nearly all from the 24-hour subset (97-100%) displayed a squamate appearance which paralleled and was caused by acute tubular necrosis. At 1 week, a dilated pars recta was common, but by this time, the squamate pattern had disappeared. Many casts were present. At 2 weeks, many fewer casts were present in proximal tubules and none were seen at 4, 8 or 12 weeks. The nephrons, particularly the proximal tubules, presented a variety of structural alterations at 2, 4, 8 and 12 weeks. Changes of special interest include (1) the presence of swan-necks; (2) a distinctive squamate appearance of the proximal tubules in the animals killed at 24 h; (3) a spiral, curled appearance caused by differential hyperplasia in animals at 4, 8 and 12 weeks, and (4) a tendency for ischemic lesions to involve all layers of the renal cortex.